2021-11-15 GC Agenda - Item 7 - Attachment 2 - Coastal Hazards Adaptation Plan with tracked changes

make shoreline recession along much of Noosa Shire’s coastline very likely (State of Queensland,
2011).17. This means that when largerhigher-intensity storm events occur in the future, the area of
land above the high-water mark susceptible to the effects of erosion will increase landward
compared to today.


What are tidal inundation and storm tides?
As the sea levels rise, low-lying areas will be exposed to more frequent inundation under everyday
conditions and also with storm tides. In addition to a worsening of inundation in locations that
already experience it, some areas not previously exposed to inundation will also be
affectedeffected. This plan deals with two types of inundation hazard – permanent tidal inundation
and storm tide inundation. In subsequent sections of this plan, these will collectively be referred to
as ‘periodic tidal inundation’.


Permanent tidal inundation

As sea levels rise, the level of tidal waters increases in elevation in relation to the shoreline,
covering low-lying areas with sea water. In practice, this will look like a very significant ‘king tide’.
Though instead of occurring every so often as occurs with ‘king tides’ today, it will instead occur
from two to three days per month in some locations, and almost every day in others (i.e. locations
close to the present-day shoreline) when the tide peaks. In the absence of any adaptation
response, this frequent or permanent inundation will mean, in some areas, the ground will be near-
permanently saturated, and in other areas, periods of reduced access to recreational areasspaces,
roads and footpaths willwhich can cause nuisance to residents and visitors alike.

To understand how far this water may travel inland, tidal waters were modelled to show the
maximum extent under calm conditions18. The results of this forby the year 2100 can be seen in
Figure 5. Additional images of permanent tidal inundation extent for the entire Noosa coastal zone
across other years can be found in Appendix 3. These map layers can also be explored in greater
detail using Council’s interactive mapping website.




17 State of Queensland (2011). Queensland Coastal Processes and Climate Change
18 For more information, see BMT WBM (2018)’s Phase 3 – Coastal Hazards Modelling Report (Noosa Shire

Council Coastal Hazards Risk, Vulnerability and Adaptation Assessment: Coastal Hazard Mapping
Refinement)
Noosa Council – Coastal Hazards Adaptation Plan                                                  Page 23